Dual sourcing power over ethernet on a single data path

ABSTRACT

Described herein is a data communication system using power over Ethernet (PoE) for power distribution, comprising a first and second powered device (PD), each of which is adapted to communicate with each other through an Ethernet data path (EDP) and is further adapted to receive direct current (DC) power using a PoE protocol, and a mid-span power injection device (MSPID) adapted to provide a communications interface such that data communications passes through the MSPID to and from each of the PDs, and wherein the MSPID is further adapted to provide a first DC power to only the first PD using the EDP, and to provide a second DC power to only the second PD using the EDP.

PRIORITY INFORMATION

The present application claims priority under 35 U.S.C. § 120 as acontinuation application to U.S. Non-Provisional patent application Ser.No. 16/671,421, filed on Nov. 1, 2019 (Attorney Docket No. CP00350-01,and now U.S. Pat. No. 11,456,884); and U.S. Pat. No. 11,456,884 claimspriority under 35 U.S.C. § 120 as a continuation application to U.S.Non-Provisional patent application Ser. No. 15/172,245, filed Jun. 3,2016 (Attorney Docket No. CP00350-00, and now U.S. Pat. No. 10,476,684),the entire contents of both of which are expressly incorporated hereinby reference.

BACKGROUND Technical Field

Aspects of the embodiments relate generally to powering Ethernet baseddevices and more particularly to systems, methods, and modes forsupplying power to Ethernet based devices using power-over-Ethernet(PoE) cabling systems via a mid-span power injection device.

Background Art

As those of skill in the art can appreciate, Ethernet technology iswidely used to transfer many different types of signals, including data,audio, and especially video. Ethernet, in many circumstances, is thetechnology of choice due to its high data throughput capacity. Onesignificant area in which it is used is high definition (HD) videotransfer devices, and even more advanced systems that utilize 4Khorizontal resolution video systems. Ethernet, however, is not limitedto just audio or video systems, but is also used, almost ubiquitously,in many intranet and internet systems.

As those of skill in the art can appreciate, all of those Ethernetdevices need to be provided with power. Most of the time, this is not anissue. Most devices are located near other sources or sinks of data, andas such, because of the nature of the use of such devices, house orbuilding power is generally available. There are circumstances, however,where Ethernet devices are not co-located with sources of power. Forexample, an Ethernet capable security video camera or remotely locateddisplay will need an external source of power. In addition, repeatersare often used for extended Ethernet runs that are located in corridorsor locations (e.g., underground, above ground, among other locations)where there might not be power, and other remote installation usesabound. In those cases, PoE is a technology that lets network cablescarry electrical power. That is, the Ethernet cable carries not only thedata signals, but also power to the device that sources or sinks thedata.

Accordingly, those of skill in the art appreciate several advantages tothe use of PoE. These include time and cost savings by not having toinstall additional power cabling. Network cables generally do not haveto be installed by qualified electricians. There is increasedflexibility in not being tethered to an electrical outlet. As such,cameras and wireless access points can be located generally whereverthey most make sense to be located, and readily repositioned if desired.Furthermore, PoE has proven to be a safe and reliable means of gettingpower to where it is needed. PoE is designed to protect networkequipment from overload, under-powering, and incorrect installation.Finally, there is an element of scalability to PoE. However, as those ofskill in the art can further appreciate, scalability is not unlimited,and there are limits as to how much power can be delivered, and for howmuch distance. Thus, there are circumstances in which remotely locatedpower supplies are needed to power Ethernet devices.

In implementation, PoE mid-span devices have been used in 100 mega-bit(Mbit) systems, and in these cases, used the spare pairs. However, whenEthernet capabilities increased to giga-bit (Gbit) transmission rates,there were no more spare pairs, as all four cables were used for datatransmissions. To get power over Gbit Ethernet cables, known systemsincorporated transformers to inject direct current (DC) power. However,as those of skill in the art can appreciate, transformers in the signalpath degrade the signals due to leakage inductance and interwindingcapacitance. At 10 Gbit rates (included, e.g., HDBaseT usages), reducedsignal integrity results in shorter allowable cable lengths, whichincreases costs.

Further, as known by those of skill in the art, most Ethernetcommunications are between a device and a switch. There are valid usecases for Ethernet devices other than switches being connected together,however. For example, a PoE camera can be connected directly to a PoEpowered monitor. Another use case is to have a PoE powered switch andcamera. This allows the switch to be located in places where no powerexists. There are also use cases that include HDBaseT extenders, whereinan Ethernet transmitter is connected to an Ethernet receiver, and bothdevices receive power via the Ethernet cable. Another example is atransmitter connected to a power-over-HDBase T (PoH) monitor.

Accordingly, a need has arisen for systems, methods, and modes forsupplying power to Ethernet based devices using PoE cabling systems viaa mid-span power injection device.

SUMMARY

It is an object of the embodiments to substantially solve at least theproblems and/or disadvantages discussed above, and to provide at leastone or more of the advantages described below.

It is therefore a general aspect of the embodiments to provide systems,methods, and modes for supplying power to Ethernet based devices usingPoE cabling systems via a mid-span power injection device that willobviate or minimize problems of the type previously described.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

According to a first aspect of the embodiments, a data communicationsystem using power over Ethernet (PoE) for power distribution isprovided comprising a first and second powered device (PD), each ofwhich is adapted to communicate with each other through an Ethernet datapath (EDP) and is further adapted to receive direct current (DC) powerusing a PoE protocol, and a mid-span power injection device (MSPID)adapted to provide a communications interface such that datacommunications passes through the MSPID to and from each of the PDs, andwherein the MSPID is further adapted to provide a first DC power to onlythe first PD using the EDP, and to provide a second DC power to only thesecond PD using the EDP.

According to the first aspect of the embodiments, the EDP comprises atleast one pair of twisted wires, each of the twisted wires of the atleast one pair of twisted wires including a first portion and a secondportion, each of the first and second portions including a first endconnected to a respect PD, and each of the first and second portionsfurther including a second end, and a pair of capacitors, each capacitorconnecting the first and second portions of a respective wire togetherat the second end of the first and second portions.

According to the first aspect of the embodiments, each of the capacitorsis adapted to pass, substantially unimpeded, a data signal between thefirst and second PD, and the MSPID comprises the capacitors for each ofthe at least one or more pairs of twisted wires, a first power sourceequipment (PSE) adapted to provide the first DC power to the first PD, asecond PSE adapted to provide the second DC power to the second PD, afirst choke adapted to pass the first DC power from the first PSE to thefirst PD, and wherein the first choke is connected to the first portionof each wire of the twisted pair of wires of the EDP connected to thefirst powered device, and a second choke adapted to pass the second DCpower from the second PSE to the second PD, and wherein the second chokeis connected to the second portion of each wire of the twisted pair ofwires of the EDP connected to the second PD.

According to the first aspect of the embodiments, the capacitors in eachwire of the Ethernet cable are further adapted to block the first DCpower from the first PSE from reaching the second PD, and tosubstantially simultaneously block the second DC power from the secondPSE from reaching the first PD.

According to the first aspect of the embodiments, the first and secondchokes each comprise a center tapped choke, the center tapped chokeincluding a center tap, a first choke output terminal, and a secondchoke output terminal, and wherein the center tap of each of the firstand second chokes are connected to their respective PSE.

According to the first aspect of the embodiments, the first choke outputterminal of the first center tapped choke is connected to the firstportion of a first twisted wire of the at least one pair of twistedwires of the EDP connected to the first PD, the second choke outputterminal of the first center tapped choke is connected to the firstportion of a second twisted wire of the at least one pair of twistedwires of the EDP connected to the first PD, the first choke outputterminal of the second center tapped choke is connected to the secondportion of a first twisted wire of the at least one pair of twistedwires of the EDP connected to the second PD, and the second choke outputterminal of the second center tapped choke is connected to the secondportion of a second twisted wire of the at least one pair of twistedwires of the EDP connected to the second PD.

According to the first aspect of the embodiments, the first chokecomprises a pair of chokes, a first terminal of each of which isconnected to each other and to an output of the first PSE, and a secondterminal of each is connected to respective first portions of first andsecond wires of the at least one pair of twisted wires of the EDP, andthe second choke comprises a pair of chokes, a first terminal of each ofwhich is connected to each other and to an output of the second PSE, anda second terminal of each is connected to respective second portions offirst and second wires of the at least one pair of twisted wires of theEDP.

According to the first aspect of the embodiments, the MSPID is furtheradapted to provide PoE using the Institute of Electrical Engineers(IEEE) PoE 802.3at protocol, and the first powered device can be one ofan audio/video transmitter or receiver, and the second powered devicecan be one of an audio/video receiver or transmitter.

According to the first aspect of the embodiments, the first powereddevice can be an Ethernet switch, and the second powered device can bean Ethernet switch. According to the first aspect of the embodiments,the first powered device can be a video player device, and the secondpowered device can be a television or monitor.

According to the first aspect of the embodiments, the data communicationsystem comprises an HDBase T Ethernet data communication system.

According to a second aspect of the embodiments, a method is providedfor providing direct current (DC) power using a power-over-Ethernet(PoE) protocol in an HDBase T data communication system, the methodcomprising installing at least two powered devices (PD) adapted tocommunicate with each other using an Ethernet data path (EDP) andfurther adapted to receive DC power using a PoE protocol and the EDP,installing a mid-span power injection device (MSPID) between the atleast two PDs, wherein the MSPID is adapted to provide a first DC powerto a first of the at least two powered devices using the PoE protocoland the EDP and without the first DC power being provided to a second ofthe at least two powered devices, and wherein the MSPID is furtheradapted to provide a second DC power to the second powered device usingthe PoE protocol and the EDP and without the second DC power beingprovided to the first powered device, and further wherein, datacommunications can occur between the first and second powered devicesusing the EDP that provides respective DC power to each of the first andsecond powered devices.

Further features and advantages of the aspects of the embodiments, aswell as the structure and operation of the various embodiments, aredescribed in detail below with reference to the accompanying drawings.It is noted that the aspects of the embodiments are not limited to thespecific embodiments described herein. Such embodiments are presentedherein for illustrative purposes only. Additional embodiments will beapparent to persons skilled in the relevant art(s) based on theteachings contained herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the embodiments will becomeapparent and more readily appreciated from the following description ofthe embodiments with reference to the following figures. Differentaspects of the embodiments are illustrated in reference figures of thedrawings. It is intended that the embodiments and figures disclosedherein are to be considered to be illustrative rather than limiting. Thecomponents in the drawings are not necessarily drawn to scale, emphasisinstead being placed upon clearly illustrating the principles of theaspects of the embodiments. In the drawings, like reference numeralsdesignate corresponding parts throughout the several views.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 illustrates a dual-sourcing isolated PoE mid-span power injectiondevice for use with two or more powered devices according to aspects ofthe embodiments.

FIG. 2 illustrates the dual sourcing PoE mid-span power injection deviceof FIG. 1 used within an HDBase T network system that transmits HDuncompressed video according to aspects of the embodiments.

FIG. 3 illustrates a flowchart of a method for injecting power via themid-span power injection device of FIGS. 1 and 2 according to aspects ofthe embodiments.

FIGS. 4A and 4B illustrate alternate aspects of the embodiments ofinductive circuit elements that can be used in the mid-span powerinjection device of FIG. 1 according to further aspects of theembodiments.

FIG. 5 illustrates a quad-sourcing isolated PoE mid-span power injectiondevice for use with two or more powered devices according to aspects ofthe embodiments.

DETAILED DESCRIPTION

The embodiments are described more fully hereinafter with reference tothe accompanying drawings, in which aspects of the embodiments areshown. In the drawings, the size and relative sizes of layers andregions may be exaggerated for clarity. Like numbers refer to likeelements throughout. The embodiments may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the aspects of the embodiments to those skilled inthe art. The scope of the embodiments is therefore defined by theappended claims. The detailed description that follows is written fromthe point of view of a control systems company, so it is to beunderstood that generally the concepts discussed herein are applicableto various subsystems and not limited to only a particular controlleddevice or class of devices, such as high definition video systems.

Reference throughout the specification to “one embodiment” or “anembodiment” means that a particular feature, structure, orcharacteristic described in connection with an embodiment is included inat least one embodiment of the embodiments. Thus, the appearance of thephrases “in one embodiment” or “in an embodiment” in various placesthroughout the specification is not necessarily referring to the sameembodiment. Further, the particular feature, structures, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

LIST OF REFERENCE NUMBERS FOR THE ELEMENTS IN THE DRAWINGS IN NUMERICALORDER

The following is a list of the major elements in the drawings innumerical order.

-   100 Dual Source Power-over-Ethernet (PoE) Mid-Span Power Injection    Device (Mid-span Power Injection Device)-   102 Powered Device-   104 Ethernet Data-Path-   108 PoE Power Sourcing Equipment Controller-   110 Center Tapped Choke-   112 Capacitor-   114 Powered Device Transmitter-   116 Powered Device Receiver-   106 Center-Tapped Transformer-   118 Load-   200 HDBase T Video Transfer System (System)-   202 DM-TX1-4K-C-1G Transmitter (Transmitter)-   204 DM-PSU Mid-span PoE supply (PoE supply)-   206 TS-1542-C-   208 Ethernet Connector, First-   210 Ethernet Connector, Second-   212 Ethernet Connector, Third-   214 Ethernet Connector, Fourth-   300 Method for Transferring Power-over-Ethernet via a Dual Source    PoE Mid-Span Power Injection Device to at Least Two Separate Powered    Devices (PDs)-   302-310 Method Steps of Method 300-   402 Choke-   502 Transceiver

LIST OF ACRONYMS USED IN THE SPECIFICATION IN ALPHABETICAL ORDER

The following is a list of the acronyms used in the specification inalphabetical order.

-   AC Alternating Current-   DC Direct Current-   EDP Ethernet Data Path-   CE Consumer Electronic-   Gbit Giga-Bit-   HD High Definition-   HDBase T Consumer electronic and commercial connectivity standard    for transmission of uncompressed high-definition video, audio,    power, home networking, Ethernet, USB, and some control signals,    over a common category cable with a standard connector (RJ45)-   IEEE Institute of Electrical and Electronics Engineers-   IP Internet Protocol-   Mbit Mega-Bit-   MSPID Mid-Span Power Injection Device-   PD Powered Device-   PoE Power-over-Ethernet-   PoH Power-over-HdBase T-   PoS Point-of-Sale-   PSE Power Sourcing Equipment-   PTZ Pan-Tilt-Zoom-   Rx Receiver-   Rx+ Receiver+-   Rx− Receiver−-   RFID Radio Frequency Identification-   TV Television-   Tx Transmitter-   Tx+ Transmitter+-   Tx− Transmitter−-   μf Micro-farads-   USB Universal Serial Bus-   VESA Video Electronics Standards Association-   V Voltage/Volt(s)-   W Watt(s)

The different aspects of the embodiments described herein pertain to thecontext of an Ethernet-based network, but is not limited thereto, exceptas may be set forth expressly in the appended claims. As known by thoseof skill in the art, most Ethernet communications are between a device(non-switch device) and a switch. There are, however, valid use casesfor two devices being connected together in which one of the devices isnot a switch, e.g., both devices are non-switch devices. For example, aPoE camera can be connected directly to a PoE powered monitor. Anotheruse case is to have a PoE powered switch and camera. This allows theswitch to be located in places were no power exists. There are also usecases that include HDBase T extenders, wherein an Ethernet transmitteris connected to an Ethernet receiver, and both devices received powervia the Ethernet cable, or a transmitter is connected to apower-over-HDBaseT (PoH) monitor. According to aspects of theembodiments, the discussion of FIGS. 1-5 includes several circuitcomponents, and frequencies of data transmission; the capacitorsdescribed therein can have a value of about 0.1 microfarads (μf), andwhich ranges from about 0.09 μf to about 1.1 μf; and theinductors/chokes described herein can have a value of about 425μ-henries (μh), and which ranges from about 382.5 μh to about 467.5 μh.The corresponding frequencies can be about 10 mega-hertz (MHz), andwhich ranges from about 9 MHz to about 11 MHz; 100 MHz, and which rangesfrom about 90 MHz to abut 110 MHz; 1 giga-hertz (GHz), and which rangesfrom about 0.9 GHz to about 1.1 GHz; and 10 GHz, and which ranges fromabout 9 GHz to about 11 GHz.

For 40 years Creston Electronics Inc., has been the world's leadingmanufacturer of advanced control and automation systems, innovatingtechnology to simplify and enhance modern lifestyles and businesses.Crestron designs, manufactures, and offers for sale integrated solutionsto control audio, video, computer, and environmental systems. Inaddition, the devices and systems offered by Crestron streamlinestechnology, improving the quality of life in commercial buildings,universities, hotels, hospitals, and homes, among other locations.Accordingly, the systems, methods, and modes of the aspects of theembodiments described herein, as embodied as dual source PoE mid-spanpower injection device (mid-span power injection device (MSPID)) 100 canbe manufactured by Crestron Electronics Inc., located in Rockleigh, N.J.

FIG. 1 illustrates Power-over-Ethernet (PoE) mid-span power injectiondevice (mid-span power injection device (MSPID) 100 for use with two ormore powered devices that utilize HdBase T communications according toaspects of the embodiments. MSPID 100 comprises first through fourthcapacitors 112 a-d, first through fourth center tapped chokes 110 a-d,and first and second power sourcing equipment controllers (PSEs) 108a,b. MSPID 100 is adapted to provide power to first powered device (PD)102 a from PSE 108 a and to provide power to second PD 102 b from PSE108 b. MSPID 100 is connected to first PD 102 a via first Ethernet datapath (EDP) 104 a and second EDP 104 b, and MSPID 100 is connected tosecond PD 102 b via third and fourth EDPs 10 c,d. Each of EDPs 104 c,dcomprise differential signal pairs of wires, generally embodied astwisted pair wires.

According to aspects of the embodiments, the manner in which first PD102 a is connected to MSPID 100 via first and second EDPs 104 a,b, andthe manner in which second PD 102 b is connected to MSPID 100 via thirdand fourth EDPs 104 c,d is adapted to substantially prevent DC voltagesfrom first and second PSEs 108 a,b from interfering with each other, andto allow Ethernet signals to flow between first and second PDs 102 a,bsubstantially unimpeded, and to substantially prevent the Ethernetsignals from interfering with, or corrupting, first and second PSEs 108a,b according to aspects of the embodiments.

As described above, each of EDPs 104 typically comprises a twisted-pairset of wires, embodied as differential signal, i.e., a “plus” and“minus” designated wire. In FIG. 1 , this is shown as Data+ (D+) andData− (D−), respectively, at both of PDs 102 a,b. As those of skill inthe art can appreciate, in some uses one of the PDs 102 can be atransmitter (in which case the respective terminations would be“transmitter” (Tx+/Tx−)), and the other “receiver” (in which case therespective terminations would be “receiver” (Rx+/Rx−)). As those ofskill in the art can further appreciate, EDPs 104 can be groupedtogether such that a cable can be formed of two or more sets of twistedpair wires, each twisted pair comprising a different differential signalpair.

According to aspects of the embodiments, first EDP 104 a is connectedfrom first PD 102 a to first and second capacitors 112 a,b in the mannershown in FIG. 1 , and third EDP 104 c is connected to first and secondcapacitors 112 a,b in a substantially similar manner That is, accordingto aspects of the embodiments, first capacitor 112 a is placed in-linein the D+ path of first EDP 104 a and third EDP 104 c, and secondcapacitor 112 b is placed in the D− path of first EDP 104 a and thirdEDP 104 c, such that alternating current (AC) signals can pass in eitherdirection through first and third EDP 104 a,c substantially unimpeded,while DC voltages are substantially blocked, in either direction, frompassing through first and second capacitors 112 a,b. A substantiallysimilar arrangement is made in regard to second and fourth EDPs 104 b,d,and third and fourth capacitors 112 c,d such that AC signals can pass ineither direction through third and fourth capacitors 112 c,dsubstantially unimpeded, while DC voltages are substantially blocked ineither direction.

In the configuration shown, and as described above, first PSE 108 aprovides power to first PD 102 a through first center tapped choke 110 ain the manner known to those of skill in the art and familiar withInstitute of Electrical and Electronic Engineers (IEEE) standard802.3at, as well as new standard 802.11bt, and any updates/upgrades/newrevisions thereto. To provide power, the PSE performs a process that isdescribed in the IEEE 802.3at standard. According to IEEE 802.3at, firstPSE 108 a interrogates first PD 102 a (and similarly, second PSE 108 binterrogates second PD 102 b), to determine what class of PD it is.According to IEEE 802.3at, the PSE applies a first and second voltage toextract a signature value. The PSE sources current, and measures voltageand impedance to determine the class of the PD. A load voltage isprovided to the PSE by connecting a known resistive load to the firstand second voltages. The PSE then performs additional voltage supplyingsteps in order to further ascertain the class of device of the PD.According to the protocol of IEEE 802.3at, the voltages are applied forcertain specific time periods, and at certain specific levels. As thoseof skill in the art can appreciate, type 1 PSEs can only provide about13 watts (W) of power, while type 2 can provide up to about 25.5 W ofpower, and future types, currently being planned, e.g., PoE++, will beable to provide even greater amounts of power (e.g., up to about 100 W).

The benefit of being able to supply larger amounts of power means that abroader range of devices can be used in PoE systems, such aspan-tilt-zoom (PTZ) internet protocol (IP) security cameras and accesscontrollers, radio frequency identification (RFID) readers, thin-clientcomputers, multi-antenna based wireless access points, 802.11n wirelessaccess points, video phones, laptops, point-of-sale (PoS) terminals,among many other types of devices.

As described above, and according to aspects of the embodiments, EDP 104provides for Ethernet transmissions of video, audio, and/or data,between first PD 102 a and second PD 102 b. Each of PDs 102 a,b,however, needs power, and for numerous reasons, may only be able toobtain such power through a PoE arrangement. In this case, first PSE 108a provides power to first PD 102 a through first center tapped choke 110a, and EDPs 104 a,b to first PD 102 a. DC voltages and current fromfirst PSE 108 a can pass through first center tapped choke 110 a to eachof the wires in EDP 104 a,b to first PD 102 a. First center tapped choke110 a also substantially prevents, or minimizes, the AC voltages of thesignals from negatively affecting first PSE 108 a, as inductors opposechanges in voltage due to their characteristic behavior in building upand releasing magnetic fields. That is, at about zero Hertz (Hz) (i.e.,DC voltages), inductors act as a short. FIGS. 4A and 4B illustratealternate aspects of the embodiments of inductive circuit elements thatcan be used in MSPID 100 of FIG. 1 according to further aspects of theembodiments.

Referring now to FIG. 4A, there is shown first and second chokes, 402a,b, connected in the manner shown such that each has a first sideconnected to the output of first PSE 108 a, and a second side of eachrespectively connected to first and second wires of EDP 104 according toaspects of the embodiments. DC current from PSE 108 a passes througheach of first and second chokes 402 a,b to the first and second wires ofEDP 104.

In FIG. 4B, center tapped choke 110 is used as the inductive element inplace of individual chokes 402 a,b of FIG. 4A. In FIG. 4B, the output offirst PSE 108 a is connected to the center tap of center tapped choke110. A first pin, pin 1, of center tapped choke 110 is connected to thefirst wire of EDP 104, and a second pin, pin 2, of center tapped choke110 is connected to the second wire of EDP 104. In this manner,therefore, DC current from PSE 108 a passes through the center tap toeach of the first and second connections of center tapped choke 110 andthrough the first and second wires of EDP 104 to a respective PD 102.

Referring back to FIG. 1 , DC voltages from first PSE 108 a that areallowed to pass through center tapped choke 110 a to the D+ and D− wiresof EDP 104 a are blocked from going to second PD 102 b because ofblocking capacitors 112 a,b according to aspects of the embodiments. Ina substantially similar manner, DC voltages from second PSE 108 b thatare allowed to pass through center tapped choke 110 c to first andsecond wires of EDP 104 c are blocked from going to first PD 102 a alsobecause of blocking capacitors 112 a,b according to aspects of theembodiments. According to aspects of the embodiments, the DC power fromeither or both of first and second PSE 108 a,b includes a positive DCvoltage/current (+V1) and a negative DC voltage/current (−V1). In thecase of first PSE 108 a, the DC voltage/current passes through centertapped transformer 106 a for +V1 from first PSE 108 a, to load 118 a.The negative voltage/current passes through center tapped transformer106 b to load 118 a; a substantially similar means for providing powerto second load 118 b occurs in regard to second PSE 108, center tappedtransformers 106 c,d and second load 118 b according to aspects of theembodiments.

Blocking capacitors 112 a,b are substantially lossless when AC signals(e.g., the HDBase T data signals) are being transmitted between first PD102 a and second PD 102 b. Thus, data (in the form of AC HDBase Tsignals, among other types) can be transferred between PDs 102 a and 102b, while DC power from first PSE 108 a is only allowed to flow to firstPD 102 a, and likewise, DC power from second PSE 108 b is only allowedto flow to second PD 102 b, in accordance with aspects of theembodiments.

According to further aspects of the embodiments, first and second PSEs108 a,b can be isolated from each other, or, alternatively, do not haveto be isolated from each other, meaning they can share common grounds.According to still further aspects of the embodiments, first and secondPSEs 108 a,b can be isolated from first and second PDs 102 a,b (meaningthey can “float” with respect to their respective endpoints), or not,according to still further aspects of the embodiments.

According to aspects of the embodiments, the value of the capacitors 112used in EDP 104 is dependent upon the expected voltage level of the ACdata signals, and the frequency (or communication rate). That is, inorder to achieve pass through, according to aspects of the embodiments,there should be low impedance in the AC data communications lines (e.g.,Ethernet lines). According to aspects of the embodiment, the value ofthe inductor or choke used to bridge the power supply to the data lines(Tx and Rx) depends on the voltage level of the power supply, and thefrequency or communication rate of the AC data signals. According tostill further aspects of the embodiments, values of the capacitors andinductors can be chosen or selected based on the expected DC voltage andcurrent levels generated by the PSE's 108 a,b, and frequency of theHDBase T data signals. Examples of such values can include, when using100 MBps Ethernet, capacitors rated to withstand 100V, with a value ofabout 0.1 microfarads (μf), according to further aspects of theembodiments.

According to still further aspects of the embodiments, first and secondPSE 108 a,b can be combined into one device (though acting as twoseparate PSEs), such that separate negotiations via the IEEE 802.3atstandard can take place between each PSE and its respective load(endpoints 102). According to aspects of the embodiments, while use ofthe IEEE 802.3at standard and conforming devices has certain advantages,it is not necessary, and the aspects of the embodiments, are not limitedto use of the standard. Therefore, according to aspects of theembodiments, endpoints 102 a,b can be IEEE 802.3at conforming devices ornot, and PSEs 108 a,b can be IEEE 802.3at conforming devices or not.

According to further aspects of the embodiments, if a non-IEEE 802.3atendpoint device, and/or PSE is used, similar handshaking process can beused as in the standard.

In FIG. 1 , PD 102 a comprises transmitter 114 a and receiver 116 a,each of which is connected to respective differential EDPs 104 a,b, viarespective center tapped transformer transceivers (transformers) 106a,b, and PD 102 b comprises transmitter 114 b and receiver 116 b, eachof which are connected respective differential EDPs 104 c,d, viarespective transformers 106 c,d, in the configuration shown in FIG. 1 .

That is, EDP 104 a (and all of the EDPs in FIGS. 1 and 5 ) comprisesData+ and Data− lines that are connected to a first side of transformer106 a, and a second side of transformer 106 a is connected totransmitter 114 a of PD 102 a. EDP 104 a is connected to EDP 104 c viacapacitors 112 a,b, so that AC voltage signals can pass substantiallyunimpeded (in both directions) while DC voltages and currents aresubstantially blocked (in both directions). Ethernet cable 104 c isconnected to a first side of transformer 106 c of PD 102 b, and a secondside of transformer 106 c is connected to receiver 116 b.

In addition, EDP 104 c comprises Data+ and Data− lines that areconnected to a first side of transformer 106 c, and a second side oftransformer 106 c is connected to receiver 116 b of PD 102 a. EDP 104 cis connected to EDP 104 d via capacitors 112 c,d, so that AC voltagesignals can pass substantially unimpeded (in both directions) while DCvoltages and currents are substantially blocked (in both directions).EDP 104 d is connected to a first side of transformer 106 d of PD 102 b,and a second side of transformer 106 d is connected to transmitter 114b.

Capacitors 112 a-d are adapted to provide DC blocking with respect tothe outputs of PSE controller 108 a and PSE controller 108 b,respectively.

That is, capacitor 112 a is provided to block +V1 VDC provided by PSEcontroller 108 a from being directed to PD 102 b on Data+ line of EDP104 c, and to substantially simultaneously block +V2 VDC provided by PSEcontroller 108 b from being directed to PD 102 a on Data+ line of EDP104 a. Capacitor 112 b is provided to block +V1 VDC provided by PSEcontroller 108 a from being directed to PD 102 b on Data− line of EDP104 c, and to substantially simultaneously block +V2 VDC provided by PSEcontroller 108 b from being directed to PD 102 a on Data− line of EDP104 a.

Capacitor 112 c is provided to block −V1 VDC provided by PSE controller108 a from being directed to PD 102 b on Data+ line of EDP 104 d, and tosubstantially simultaneously block −V2 VDC provided by PSE controller108 b from being directed to PD 102 a on Data+ line of EDP 104 b.Capacitor 112 d is provided to block −V1 VDC provided by PSE controller108 a from being directed to PD 102 b on Data− line of EDP 104 d, and tosubstantially simultaneously block −V2 VDC provided by PSE controller108 b from being directed to PD 102 a on Data− line of EDP 104 b.

Also included in FIG. 1 (as well as in FIG. 5 ), are a plurality ofloads. In FIG. 1 , there is shown first load 118 a, associated with PD102 a, and second load 118 b, associated with PD 102 b. Each of loads118 a,b can be circuitry associated with PDs 102 a,b, and can includethe need for positive and negative voltages, as well as convertors thatcan change the DC voltages to different levels, including AC voltages.

FIG. 2 illustrates use of MSPID 100 in HDBase T network system (system)200 that transmits HD uncompressed video according to aspects of theembodiments. System 200 comprises, by way of non-limiting example only,DM-TX1-4K-C-1G transmitter (transmitter) 202 (PD1), DM-PSU Mid-span PoEsupply (PoE supply) 204, and TS-1542-C (PD2) 206. The DM-TX1-4K-C-1Gprovides a 1-gang mountable interface for a HD or 4K source as part of acomplete DigitalMedia™ System. The DM-TX1-4K-C-1G can connect to a DM8G+® input of a DM® switcher or receiver, and can be powered by the PoEmid-span supply 204, via a single CATx Ethernet cable. The TS-1542-Cdevice provide a full HD 1080p touch screen suitable for installation ona wall, tabletop, or Video Electronics Standards Association (VESA),which is a family of standards defined by VESA for mounting flat panelmonitors, TVs, and other displays to stands or wall mounts. It isimplemented on most modern flat-panel monitors and TVs. The TS-1542-Cfeature Smart Graphics performance, dual-window HD streaming videodisplay, annotation, voice recognition, web browsing, and Rava SIPintercommunications, among other features. Further, the TS-1542-Cconnects to the DM 8G+ output of a DM switcher or transmitter, and canbe powered by the PoE mid-span supply 204, via a single CATx Ethernetcable.

As shown in FIG. 2 , PoE power is transmitted along the 4 line EthernetCable (four differential pairs; see, FIG. 5 for an illustration of fourdifferential pairs of Ethernet cable in a system that injects PoEaccording to aspects of the embodiments) by mid-span PoE injector 204.PD 1, which in this example, comprises Ethernet connector 208 thatconnects EDP 104 a to Ethernet connector 210 at mid-span PoE 204, andEthernet connector 212 provides a connection for EDP 104 b that isconnected to PD 2 at Ethernet connector 214. According to furtheraspects of the embodiments, as shown in FIG. 2 , each of PD1 202 and PD2206 can comprise a plurality of different devices designed to work withcorresponding devices. For example, in the box there is shown, underPD1, Blue Ray Player, which corresponds to (or which can be incommunication with) a television (TV) set and/or monitor, listed underPD2. Other devices are listed under PD1 that correspond to a second listunder PD2. As those of skill in the art can appreciate, these lists aremerely examples of some devices that can be used with othercorresponding devices, and such a list is not, and should be taken in alimiting manner.

HDBase T, promoted and advanced by the HDBase T Alliance, is a consumerelectronic (CE) and commercial connectivity standard for transmission ofuncompressed HD, audio, power, home networking, Ethernet, universalserial bus (USB), and some control signals, over a common category(Cat5e or above) cable with a standard connector (RJ45).

As described above, FIG. 5 illustrates a quad-sourcing isolated PoEmid-span power injection device 100 for use with two or more Ethernetendpoint devices according to aspects of the embodiments. The system ofFIG. 5 is substantially similar to that of FIG. 1 , with the exceptionof there being four EDPs 104 a-d, eight capacitors 112 a-h, eight centertapped chokes 110 a-h, eight center tapped transformers 106 a-h, andother changes to incorporate the increased number of EDPs. Further, thetransmitters and receivers of FIG. 1 have been replaced withtransceivers 502 a-h. However, as those of skill in the art canappreciate based on the discussion of FIG. 1 , the circuitry of FIG. 5operates in a substantially similar manner as that of FIG. 1 .Therefore, in fulfillment of the dual purposes of clarity and brevity, adetailed discussion of FIG. 5 has been omitted from herein.

FIG. 3 illustrates a flowchart of method 300 for injecting power toEthernet endpoint devices in an Ethernet network using MDPID 100 of FIG.1 according to aspects of the embodiments.

Method 300 begins with method step 302, in which an HDBase Tcommunications system/network is set up, including at least one MSPID100, and with at least a first and second PD 102 a,b according toaspects of the embodiments. For the sole purposes of making thediscussion of method 300 satisfy the dual purposes of clarity andbrevity, and not to be taken in a limiting manner, discussion shall bemade of center tapped chokes 110 a,b in the manner shown in FIG. 1 inMSPID 100, though as those of skill in the art can now appreciate, theuse of individual chokes 402 a,b or a single side of a transformer canalso be implemented, as well as their respective equivalents, accordingto further aspects of the embodiments.

In method step 304, the user connects first PSE 108 a to EDP 104 athrough first center tapped choke 110 a, such that DC power (+V1) fromPSE 108 a passes through first center tapped choke 110 a to each of thefirst and second wires (i.e., the twisted pair) of EDP 104 a. That is,the +V1 output of PSE 108 a is connected to the center tap of centertapped choke 110 a, and a first output is connected to the first wire ofEDP 104 a, and the second output is connected to the second wire of EDP104 a. Further in method step 304, the user connects second PSE 108 b toEDP 104 c through third center tapped choke 110 c such that DC power(+V2) from PSE 108 b passed through third center tapped choke 110 c toeach of the first and second wires (i.e., the twisted pair) of EDP 104 c(in a substantially similar manner as that of first PSE 108 a beingconnected to EDP 104 a through first center tapped choke 110 a).

In addition, also in method step 304, the user locates first capacitor112 a in the first wire of EDP 104 a and 104 c (such that the two firstwires are connected to each other through first capacitor 112 a) and theuser locates second capacitor 112 b in the second wire of EDP 104 a and104 c (such that the two second wire are connected to each other throughsecond capacitor 112 b) according to aspects of the embodiments, suchthat DC voltage (+V1 and +V2) and current passes through first and thirdchokes 110 a,c to their respective PDs 102 a,b, but is blocked by firstand second capacitors 112 a,b, and that AC voltage and currents areblocked by first and third center tapped chokes 110 a,c, and passesthrough first and second capacitors 112 a,b, according to furtheraspects of the embodiments.

As those of skill in the art can appreciate, method step 304 can be doneduring manufacture of MSPID 100 prior to interfacing it with EDPs 104a-d such that upon connection between first and second EDPs 104 a,b toMSPID 100, and upon connection between third and fourth EDPs 104 c,d toMSPID 100 (and additional EDPs 104, if that is the case), suchinterconnections as described above in regard to the capacitors andchokes is already in place.

In method steps 306 and 308, presuming that IEEE 802.3at conformingdevices being used, the handshaking as described in the IEEE 802.3atstandard is performed, such that a classification of endpointdevices—PDs 102 a,b—can be ascertained. However, as described above, useof MSPID 100 is not constrained to IEEE 802.3at devices, or similarones, and can be used in Ethernet networks in which much higher (orlower) power levels are or can be used. Following either method step306, or 308, method step 310 is performed and the required amount ofpower is sent by first and second PSE 108 a,b to their respective firstand second PDs 102 a,b. As those of skill in the art can appreciate, theaspects of the embodiments, are not limited to just a first and secondPSEs 108 a,b, nor to only first and second PDs 102 a,b; that is, therecan be a single large PSE within MSPID 100, and numerous PDs 102. Whileaspects of the embodiments are directed to isolating the power supplyoutput between pairs of PDs, such is not to be taken in a limitingmanner That is, it is possible to have an HDBase T network in which asingle PD, e.g., 102 a, is connected to multiple other PDs 102 b,c,d,and each of them are power isolated from each other in a substantiallysimilar arrangement as that shown in FIG. 1 , according to furtheraspects of the embodiments.

INDUSTRIAL APPLICABILITY

To solve the aforementioned problems, the aspects of the embodiments aredirected towards systems, methods, and modes for supplying power toEthernet based devices using power-over-Ethernet (PoE) cabling systemsvia a mid-span power injection device.

The disclosed embodiments provide a system, software, and method fortransferring power over Ethernet cable via a dual source PoE MD PID 100to at Least two separate endpoints/PDs. It should be understood thatthis description is not intended to limit the embodiments. On thecontrary, the embodiments are intended to cover alternatives,modifications, and equivalents, which are included in the spirit andscope of the embodiments as defined by the appended claims. Further, inthe detailed description of the embodiments, numerous specific detailsare set forth to provide a comprehensive understanding of the claimedembodiments. However, one skilled in the art would understand thatvarious embodiments may be practiced without such specific details.

Although the features and elements of aspects of the embodiments aredescribed being in particular combinations, each feature or element canbe used alone, without the other features and elements of theembodiments, or in various combinations with or without other featuresand elements disclosed herein.

This written description uses examples of the subject matter disclosedto enable any person skilled in the art to practice the same, includingmaking and using any devices or systems and performing any incorporatedmethods. The patentable scope of the subject matter is defined by theclaims, and may include other examples that occur to those skilled inthe art. Such other examples are intended to be within the scope of theclaims.

The above-described embodiments are intended to be illustrative in allrespects, rather than restrictive, of the embodiments. Thus theembodiments are capable of many variations in detailed implementationthat can be derived from the description contained herein by a personskilled in the art. No element, act, or instruction used in thedescription of the present application should be construed as criticalor essential to the embodiments unless explicitly described as such.Also, as used herein, the article “a” is intended to include one or moreitems.

All United States patents and applications, foreign patents, andpublications discussed above are hereby incorporated herein by referencein their entireties.

Alternate Embodiments

Alternate embodiments may be devised without departing from the spiritor the scope of the different aspects of the embodiments.

What is claimed is:
 1. A data communication system using power overEthernet (PoE) for power distribution, comprising: a first and secondpowered device (PD), each of which is adapted to communicate with eachother through a first Ethernet data path (EDP) and is further adapted toreceive direct current (DC) power using a PoE protocol; and a mid-spanpower injection device (MSPID) adapted to provide a communicationsinterface such that data communications passes through the MSPID to andfrom each of the PDs, and wherein the MSPID is further adapted toprovide a first DC power to the first PD using the first EDP, and toprovide a second DC power to the second PD using the first EDP, whereineach of the first and second EDPs comprises one pair of twisted wires,each of the twisted wires of the one pair of twisted wires including afirst portion and a second portion, each of the first and secondportions including a first end connected to a respective PD, and each ofthe first and second portions further including a second end, and a pairof capacitors, each capacitor connecting the first and second portionsof a respective wire together at the second end of the first and secondportions.